Update a comment describing bpf_iflist to indicate that the BPF interface

structures correspond to specific link layers, so the same network
interface may appear more than once.

MFC after:	3 days

1 files changed, 4 insertions, 1 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 234e414..a9734ab 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -89,7 +89,10 @@ SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
 	&bpf_maxbufsize, 0, "");
 
 /*
- *  bpf_iflist is the list of interfaces; each corresponds to an ifnet
+ * bpf_iflist is a list of BPF interface structures, each corresponding to a
+ * specific DLT.  The same network interface might have several BPF interface
+ * structures registered by different layers in the stack (i.e., 802.11
+ * frames, ethernet frames, etc).
  */
 static LIST_HEAD(, bpf_if)	bpf_iflist;
 static struct mtx	bpf_mtx;		/* bpf global lock */